Solutions for a connected world

Lightening automobile vehicles

For every automaker, it is absolutely essential to make vehicles lighter. For this reason ACOME proposes a number of approaches to reduce the weight of harnesses.

   

With increased numbers of equipment and larger sizes, the weight of vehicles has been increasing for a long time (20 kg per year in Europe). But for some time, manufacturers have been reversing the tendency, especially since regulations are moving them in this direction. Euro DV1 standards indeed require a reduction in vehicle pollutant emissions. 75% of fuel consumption is related directly to the weight of the car. This means that reducing the weight of a vehicle by 100 kg is equivalent to reducing the fuel economy by 11 g of CO2 per kilometer. In addition, if they fail to comply with the regulation, the manufacturer is required to pay financial penalties. That is why manufacturers have set themselves the goal of quickly reducing the weight of the vehicle by 100 or so kilograms, then by 200 kg by the year 2020.

Several openings are being investigated by automakers:

- reducing some thicknesses by butted sheet metals;

- the deployment of aluminum alloys for some body parts and for the body itself;

- The use of magnesium and titanium alloys (for instance for the connecting rods);

- Recourse to composites (carbon, glass and vegetable fibers…);

- The use of lighter components (structural foam), aluminum honeycomb structures, expanded polypropylene, etc.;

- the optimization of engine settings and vehicle sizing.

For cable industries, the only way of reducing cable weight is to create new wires with reduced conducting sections (from 0.35 mm² to 0.22 mm² or 0.13 mm²). But ACOME believes that there is also a complementary approach to the work, based on better using the properties of the existing wires.

ACOME's reflection on reducing harness weight is based on 2 complementary methods:

- a thermal approach which consists in using the excellent mechanical high-temperature properties of reticulated polyethylene to reduce the amount of copper. The use of reticulated polyethylene enables manufacturers to modify their internal sizing rules² as a way of reducing the weight of copper;

- the mechanical approach which consists in developing electric conductors using new metallic materials. This technique is a way of decreasing the sections of small wires (0.22 mm²; 0.13 mm² and soon 0.08 mm²) while preserving the mechanical properties of the larger copper wires.

To help manufacturers reduce weight factors, ACOME accompanies them in optimizing the thermoelectric sizing of the harnesses. This assistance takes place directly or in conjunction with the cabling specialists. European manufacturers have drawn on ACOME's expertise in optimizing their harness dimensioning rules. Thanks to the characteristics of ACOME insulators, they have made gains in several kilograms of copper per vehicle.

1. http://europa.eu/legislation_summaries/environment/air_pollution/l28186_fr.htm
http://fr.wikipedia.org/wiki/Norme_europ%C3%A9enne_d'%C3%A9mission_Euro

² Each manufacturer sets out its own rules for cable dimensioning. These rules define in particular the sections of the cables used for their vehicles.